/*
 * @BEGIN LICENSE
 *
 * Psi4: an open-source quantum chemistry software package
 *
 * Copyright (c) 2007-2024 The Psi4 Developers.
 *
 * The copyrights for code used from other parties are included in
 * the corresponding files.
 *
 * This file is part of Psi4.
 *
 * Psi4 is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * Psi4 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with Psi4; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * @END LICENSE
 */

/*! \file
    \ingroup CCENERGY
    \brief Enter brief description of file here
*/
#include "psi4/libdpd/dpd.h"
#include "Params.h"
#include "MOInfo.h"
#include "psi4/cc/ccwave.h"

namespace psi {
namespace ccenergy {

/* cc3_Wmnie(): Compute the Wmnie matrix from CC3 theory, which is
** given in spin-orbitals as:
**
** Wmnie = <mn||ie> + t_i^f <mn||fe>
**
** TDC, Feb 2004
*/

void purge_Wmnie();

void CCEnergyWavefunction::cc3_Wmnie() {
    dpdbuf4 E, D, W, Z;
    dpdfile2 tIA, tia;

    if (params_.ref == 0) { /** RHF **/

        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 0, 10, 0, 10, 0, "E <ij|ka>");
        global_dpd_->buf4_copy(&E, PSIF_CC3_HET1, "CC3 WMnIe (Mn,Ie)");
        global_dpd_->buf4_close(&E);

        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 0, 10, 0, 10, 0, "CC3 WMnIe (Mn,Ie)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 0, 5, 0, 5, 0, "D <ij|ab>");
        global_dpd_->file2_init(&tIA, PSIF_CC_OEI, 0, 0, 1, "tIA");
        global_dpd_->contract244(&tIA, &D, &W, 1, 2, 1, 1, 1);
        global_dpd_->file2_close(&tIA);
        global_dpd_->buf4_close(&D);
        global_dpd_->buf4_close(&W);
    }

    else if (params_.ref == 1) { /* ROHF */

        /** W(M>N,IE) <--- <MN||IE> **/
        /** W(m>n,ie) <--- <mn||ie> **/
        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 2, 10, 2, 10, 0, "E <ij||ka> (i>j,ka)");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 2, 11, "CC3 WMNIE (M>N,EI)");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 2, 11, "CC3 Wmnie (m>n,ei)");
        global_dpd_->buf4_close(&E);

        /** W(Mn,Ie) <--- <Mn|Ie> **/
        /** W(mN,iE) <--- <mN|iE> **/
        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 0, 10, 0, 10, 0, "E <ij|ka>");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 0, 11, "CC3 WMnIe (Mn,eI)");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 0, 11, "CC3 WmNiE (mN,Ei)");
        global_dpd_->buf4_close(&E);

        /**** Term 2 ****/

        global_dpd_->file2_init(&tIA, PSIF_CC_OEI, 0, 0, 1, "tIA");
        global_dpd_->file2_init(&tia, PSIF_CC_OEI, 0, 0, 1, "tia");

        /* <M>N||EF> T(I,F) --> W(M>N,EI) */
        /* <m>n||ef> T(i,f) --> W(m>n,ei) */
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 2, 11, 2, 11, 0, "CC3 WMNIE (M>N,EI)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 2, 5, 2, 5, 0, "D <ij||ab> (i>j,ab)");
        global_dpd_->contract424(&D, &tIA, &W, 3, 1, 0, -1, 1.0);
        global_dpd_->buf4_close(&W);

        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 2, 11, 2, 11, 0, "CC3 Wmnie (m>n,ei)");
        global_dpd_->contract424(&D, &tia, &W, 3, 1, 0, -1, 1.0);
        global_dpd_->buf4_close(&D);
        global_dpd_->buf4_close(&W);

        /* Z(nM,eI) = <nM|eF> T(I,F) */
        global_dpd_->buf4_init(&Z, PSIF_CC_TMP1, 0, 0, 11, 0, 11, 0, "Z(nM,eI)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 0, 5, 0, 5, 0, "D <ij|ab>");
        global_dpd_->contract424(&D, &tIA, &Z, 3, 1, 0, 1, 0);
        global_dpd_->buf4_close(&D);
        /* Z(nM,eI) --> W(Mn,eI) */
        global_dpd_->buf4_sort_axpy(&Z, PSIF_CC3_HET1, qprs, 0, 11, "CC3 WMnIe (Mn,eI)", 1);
        global_dpd_->buf4_close(&Z);

        /* Z(Nm,Ei) = <Nm|Ef> T(i,f) */
        global_dpd_->buf4_init(&Z, PSIF_CC_TMP1, 0, 0, 11, 0, 11, 0, "Z(Nm,Ei)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 0, 5, 0, 5, 0, "D <ij|ab>");
        global_dpd_->contract424(&D, &tia, &Z, 3, 1, 0, 1, 0);
        global_dpd_->buf4_close(&D);
        /* Z(Nm,Ei) --> W(mN,Ei) */
        global_dpd_->buf4_sort_axpy(&Z, PSIF_CC3_HET1, qprs, 0, 11, "CC3 WmNiE (mN,Ei)", 1);
        global_dpd_->buf4_close(&Z);

        /* purge (mn,ei)'s before sorting */
        purge_Wmnie();

        /* also put "normal" sorted versions in CC3_HET1 */
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 2, 11, 2, 11, 0, "CC3 WMNIE (M>N,EI)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 2, 10, "CC3 WMNIE (M>N,IE)");
        global_dpd_->buf4_close(&W);
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 2, 11, 2, 11, 0, "CC3 Wmnie (m>n,ei)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 2, 10, "CC3 Wmnie (m>n,ie)");
        global_dpd_->buf4_close(&W);
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 0, 11, 0, 11, 0, "CC3 WMnIe (Mn,eI)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 0, 10, "CC3 WMnIe (Mn,Ie)");
        global_dpd_->buf4_close(&W);
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 0, 11, 0, 11, 0, "CC3 WmNiE (mN,Ei)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 0, 10, "CC3 WmNiE (mN,iE)");
        global_dpd_->buf4_close(&W);

        global_dpd_->file2_close(&tIA);
        global_dpd_->file2_close(&tia);

    }

    else if (params_.ref == 2) {
        /** W(M>N,IE) <--- <MN||IE> **/
        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 2, 20, 2, 20, 0, "E <IJ||KA> (I>J,KA)");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 2, 21, "CC3 WMNIE (M>N,EI)");
        global_dpd_->buf4_close(&E);

        /** W(m>n,ie) <--- <mn||ie> **/
        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 12, 30, 12, 30, 0, "E <ij||ka> (i>j,ka)");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 12, 31, "CC3 Wmnie (m>n,ei)");
        global_dpd_->buf4_close(&E);

        /** W(Mn,Ie) <--- <Mn|Ie> **/
        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 22, 24, 22, 24, 0, "E <Ij|Ka>");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 22, 25, "CC3 WMnIe (Mn,eI)");
        global_dpd_->buf4_close(&E);

        /** W(mN,iE) <--- <mN|iE> **/
        global_dpd_->buf4_init(&E, PSIF_CC_EINTS, 0, 23, 27, 23, 27, 0, "E <iJ|kA>");
        global_dpd_->buf4_sort(&E, PSIF_CC3_HET1, pqsr, 23, 26, "CC3 WmNiE (mN,Ei)");
        global_dpd_->buf4_close(&E);

        /**** Term 2 ****/

        global_dpd_->file2_init(&tIA, PSIF_CC_OEI, 0, 0, 1, "tIA");
        global_dpd_->file2_init(&tia, PSIF_CC_OEI, 0, 2, 3, "tia");

        /* <M>N||EF> T(I,F) --> W(M>N,EI) */
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 2, 21, 2, 21, 0, "CC3 WMNIE (M>N,EI)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 2, 5, 2, 5, 0, "D <IJ||AB> (I>J,AB)");
        global_dpd_->contract424(&D, &tIA, &W, 3, 1, 0, -1, 1.0);
        global_dpd_->buf4_close(&D);
        global_dpd_->buf4_close(&W);

        /* <m>n||ef> T(i,f) --> W(m>n,ei) */
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 12, 31, 12, 31, 0, "CC3 Wmnie (m>n,ei)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 12, 15, 12, 15, 0, "D <ij||ab> (i>j,ab)");
        global_dpd_->contract424(&D, &tia, &W, 3, 1, 0, -1, 1.0);
        global_dpd_->buf4_close(&D);
        global_dpd_->buf4_close(&W);

        /* Z(nM,eI) = <nM|eF> T(I,F) */
        global_dpd_->buf4_init(&Z, PSIF_CC_TMP1, 0, 23, 25, 23, 25, 0, "Z(nM,eI)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 23, 29, 23, 29, 0, "D <iJ|aB>");
        global_dpd_->contract424(&D, &tIA, &Z, 3, 1, 0, 1, 0);
        global_dpd_->buf4_close(&D);
        /* Z(nM,eI) --> W(Mn,eI) */
        global_dpd_->buf4_sort_axpy(&Z, PSIF_CC3_HET1, qprs, 22, 25, "CC3 WMnIe (Mn,eI)", 1);
        global_dpd_->buf4_close(&Z);

        /* Z(Nm,Ei) = <Nm|Ef> T(i,f) */
        global_dpd_->buf4_init(&Z, PSIF_CC_TMP1, 0, 22, 26, 22, 26, 0, "Z(Nm,Ei)");
        global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 22, 28, 22, 28, 0, "D <Ij|Ab>");
        global_dpd_->contract424(&D, &tia, &Z, 3, 1, 0, 1, 0);
        global_dpd_->buf4_close(&D);
        /* Z(Nm,Ei) --> W(mN,Ei) */
        global_dpd_->buf4_sort_axpy(&Z, PSIF_CC3_HET1, qprs, 23, 26, "CC3 WmNiE (mN,Ei)", 1);
        global_dpd_->buf4_close(&Z);

        /* also put "normal" sorted versions in CC3_HET1 */
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 2, 21, 2, 21, 0, "CC3 WMNIE (M>N,EI)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 2, 20, "CC3 WMNIE (M>N,IE)");
        global_dpd_->buf4_close(&W);
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 12, 31, 12, 31, 0, "CC3 Wmnie (m>n,ei)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 12, 30, "CC3 Wmnie (m>n,ie)");
        global_dpd_->buf4_close(&W);
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 22, 25, 22, 25, 0, "CC3 WMnIe (Mn,eI)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 22, 24, "CC3 WMnIe (Mn,Ie)");
        global_dpd_->buf4_close(&W);
        global_dpd_->buf4_init(&W, PSIF_CC3_HET1, 0, 23, 26, 23, 26, 0, "CC3 WmNiE (mN,Ei)");
        global_dpd_->buf4_sort(&W, PSIF_CC3_HET1, pqsr, 23, 27, "CC3 WmNiE (mN,iE)");
        global_dpd_->buf4_close(&W);

        global_dpd_->file2_close(&tIA);
        global_dpd_->file2_close(&tia);
    }
}

/* Purge Wmnie matrix elements */
void CCEnergyWavefunction::purge_Wmnie() {
    dpdfile4 W;
    int *occpi, *virtpi;
    int e, i, m, n;
    int E, I, M, N;
    int esym, isym, msym, nsym;
    int *occ_off, *vir_off;
    int *occ_sym, *vir_sym;
    int *openpi, nirreps;

    nirreps = moinfo_.nirreps;
    occpi = moinfo_.occpi;
    virtpi = moinfo_.virtpi;
    occ_off = moinfo_.occ_off;
    vir_off = moinfo_.vir_off;
    occ_sym = moinfo_.occ_sym;
    vir_sym = moinfo_.vir_sym;
    openpi = moinfo_.openpi;

    global_dpd_->file4_init(&W, PSIF_CC3_HET1, 0, 0, 11, "CC3 WMnIe (Mn,eI)");
    for (int h = 0; h < nirreps; h++) {
        global_dpd_->file4_mat_irrep_init(&W, h);
        global_dpd_->file4_mat_irrep_rd(&W, h);
        for (int mn = 0; mn < W.params->rowtot[h]; mn++) {
            n = W.params->roworb[h][mn][1];
            nsym = W.params->qsym[n];
            N = n - occ_off[nsym];
            for (int ei = 0; ei < W.params->coltot[h]; ei++) {
                if (N >= (occpi[nsym] - openpi[nsym])) W.matrix[h][mn][ei] = 0.0;
            }
        }
        global_dpd_->file4_mat_irrep_wrt(&W, h);
        global_dpd_->file4_mat_irrep_close(&W, h);
    }

    global_dpd_->file4_init(&W, PSIF_CC3_HET1, 0, 2, 11, "CC3 WMNIE (M>N,EI)");
    for (int h = 0; h < W.params->nirreps; h++) {
        global_dpd_->file4_mat_irrep_init(&W, h);
        global_dpd_->file4_mat_irrep_rd(&W, h);
        for (int mn = 0; mn < W.params->rowtot[h]; mn++) {
            for (int ei = 0; ei < W.params->coltot[h]; ei++) {
                e = W.params->colorb[h][ei][0];
                esym = W.params->rsym[e];
                E = e - vir_off[esym];
                if (E >= (virtpi[esym] - openpi[esym])) W.matrix[h][mn][ei] = 0.0;
            }
        }
        global_dpd_->file4_mat_irrep_wrt(&W, h);
        global_dpd_->file4_mat_irrep_close(&W, h);
    }
    global_dpd_->file4_close(&W);
    global_dpd_->file4_init(&W, PSIF_CC3_HET1, 0, 2, 11, "CC3 Wmnie (m>n,ei)");
    for (int h = 0; h < nirreps; h++) {
        global_dpd_->file4_mat_irrep_init(&W, h);
        global_dpd_->file4_mat_irrep_rd(&W, h);
        for (int mn = 0; mn < W.params->rowtot[h]; mn++) {
            m = W.params->roworb[h][mn][0];
            n = W.params->roworb[h][mn][1];
            msym = W.params->psym[m];
            nsym = W.params->qsym[n];
            M = m - occ_off[msym];
            N = n - occ_off[nsym];
            for (int ei = 0; ei < W.params->coltot[h]; ei++) {
                i = W.params->colorb[h][ei][1];
                isym = W.params->ssym[i];
                I = i - occ_off[isym];
                if ((M >= (occpi[msym] - openpi[msym])) || (N >= (occpi[nsym] - openpi[nsym])) ||
                    (I >= (occpi[isym] - openpi[isym])))
                    W.matrix[h][mn][ei] = 0.0;
            }
        }
        global_dpd_->file4_mat_irrep_wrt(&W, h);
        global_dpd_->file4_mat_irrep_close(&W, h);
    }
    global_dpd_->file4_close(&W);

    global_dpd_->file4_init(&W, PSIF_CC3_HET1, 0, 0, 11, "CC3 WmNiE (mN,Ei)");
    for (int h = 0; h < nirreps; h++) {
        global_dpd_->file4_mat_irrep_init(&W, h);
        global_dpd_->file4_mat_irrep_rd(&W, h);
        for (int mn = 0; mn < W.params->rowtot[h]; mn++) {
            m = W.params->roworb[h][mn][0];
            msym = W.params->psym[m];
            M = m - occ_off[msym];
            for (int ei = 0; ei < W.params->coltot[h]; ei++) {
                e = W.params->colorb[h][ei][0];
                i = W.params->colorb[h][ei][1];
                esym = W.params->rsym[e];
                isym = W.params->ssym[i];
                E = e - vir_off[esym];
                I = i - occ_off[isym];
                if ((M >= (occpi[msym] - openpi[msym])) || (E >= (virtpi[esym] - openpi[esym])) ||
                    (I >= (occpi[isym] - openpi[isym])))
                    W.matrix[h][mn][ei] = 0.0;
            }
        }
        global_dpd_->file4_mat_irrep_wrt(&W, h);
        global_dpd_->file4_mat_irrep_close(&W, h);
    }
    global_dpd_->file4_close(&W);
}

}  // namespace ccenergy
}  // namespace psi
